MCE IGCSE CS PPT C05

Chapter Overview

  • This chapter focuses on the internet and cyber security, including the following topics:

    • Differences between the internet and the World Wide Web

    • Understanding Uniform Resource Locators (URLs)

    • Hypertext Transfer Protocols (HTTP and HTTPS)

    • Functions of web browsers

    • Retrieval and location of web pages

    • The role of cookies (session and persistent)

    • Digital currencies and blockchain technology

    • Cyber security threats and protective solutions

Understanding the Internet

Definition

  • The internet is a global network consisting of interconnected computers and devices.

Function

  • Serves as the backbone for services like email, file sharing, online gaming, and the World Wide Web.

Components

  • Physical infrastructure: cables, satellites, routers, servers.

  • Protocols: TCP/IP, DNS.

The World Wide Web (WWW)

Definition

  • The WWW is a service on the internet enabling access to a vast collection of interconnected digital documents (webpages).

Function

  • Allows sharing and retrieval of information using HTTP/HTTPS protocols.

Components

  • Webpages written in HTML.

  • Web servers hosting webpages.

  • Web browsers (e.g., Chrome, Firefox) used to access these pages.

Uniform Resource Locators (URLs)

Purpose

  • URLs allow users to locate websites by typing the address into a web browser's address bar.

Structure

  • Protocol, domain name, web page/file name.

  • Each URL corresponds to an Internet Protocol (IP) address.

Example Components

  • Protocol: http/https

  • Domain name: example.com

  • Folder structure and page name: /path/to/page

Web Browsers

Definition

  • The primary application used to retrieve and display web pages.

Features

  • Supports HTML, JavaScript; facilitates tabs, bookmarks, user history, cookies management, and navigation tools.

Locating Web Pages

Retrieval Process

  • Browsers identify web pages via IP addresses.

Domain Name System (DNS)

  • System translating domain names into IP addresses for browser access.

Cookies

Definition

  • Small text files stored on computers while browsing the web.

Functions

  • Store user preferences, login details, track behavior, maintain shopping carts.

  • Help advertisers target relevant ads based on browsing habits.

Digital Currency

Characteristics

  • Exists purely in digital form; serves as a method of payment for goods/services.

Functionality

  • Transferable between accounts similar to cash/credit cards; facilitates online banking.

Cryptography

Purpose

  • Converts plain text into unintelligible formats to secure data.

Application for Digital Currency

  • Cryptocurrency uses cryptography to ensure transaction security and transparency.

Blockchain Technology

Definition

  • A decentralized database recording transactions among network members.

Functionality

  • Data is stored across multiple computers; any new transaction updates all copies within the network.

Applications

  • Used in cryptocurrency exchanges, smart contracts, and various industries such as education and pharmaceuticals.

Cyber Security

Definition

  • The practice of protecting systems, networks, devices, and data from digital attacks.

Importance

  • Combines technology and processes to safeguard information against cyber threats.

Types of Cyber Security Threats

Common Threats

  • Brute force attacks, data interception, DDoS attacks, hacking, malware, phishing, social engineering.

Security Solutions

Key Strategies

  • Implementing firewalls and anti-malware software, setting access levels, using authentication methods such as biometrics and two-factor verification.

Best Practices

  • Regular updates, careful inspection of URLs and email links, maintaining strong password conditions.

Exam Preparation Questions

Example Questions

  • Describe the difference between 'pharming' and 'phishing'.

  • Explain how a firewall operates to protect a network.

  • List common types of malware and examples of their impacts.